updated a link

Author: kthyng

cmocean/_sources/index.txt

@@ -359,7 +359,7 @@ cmocean available elsewhere!
 * For `MATLAB <http://www.mathworks.com/matlabcentral/fileexchange/57773-cmocean-perceptually-uniform-colormaps>`_ by `Chad Greene <http://www.chadagreene.com/>`_
 * For R: `Oce <http://dankelley.github.io/oce/>`_ oceanographic analysis package by `Dan Kelley <http://www.dal.ca/faculty/science/oceanography/people/faculty/daniel-e-kelley.html>`_ and `Clark Richards <http://clarkrichards.org/>`_
 * For `Ocean Data Viewer <https://github.com/kthyng/cmocean-odv>`_
-* For `Generic Mapping Tools (GMT)  <https://github.com/kthyng/cmocean-gmt>`_
+* For Generic Mapping Tools (GMT)  at `cpt-city <http://soliton.vm.bytemark.co.uk/pub/cpt-city/cmocean/index.html>`_ and on `github <https://github.com/kthyng/cmocean-gmt>`_
 * For `Paraview <https://github.com/kthyng/cmocean-paraview>`_, inspired by `Phillip Wolfram <https://github.com/pwolfram>`_.
 * In `Plotly <https://plot.ly/python/cmocean-colorscales/>`_
 * Chad Greene's `Antartic Mapping Tools <http://www.mathworks.com/matlabcentral/fileexchange/47638-antarctic-mapping-tools>`_ in Matlab uses cmocean